Association study of functional polymorphisms of dopaminergic pathway in epilepsy-related factors of temporal lobe epilepsy in Brazilian population.

BACKGROUND AND PURPOSE: There are few data about the role of neurotransmission modulated by dopamine in epilepsy, especially temporal lobe epilepsy (TLE). This is the first study that aimed to analyze the dopaminergic polymorphisms in an etiologically homogeneous group of patients with TLE with hippocampal sclerosis. Selected polymorphisms were: (i) the most expressed D2-like receptors in the limbic system (DRD2/ANKK1 TAQ-1A, D4_VNTR and D4_rs1800955); (ii) the dopamine transporter (DAT) 3'-untranslated region and intron 8; and (iii) two degrading enzymes regulating the synaptic activity, i.e. the main metabolizer of dopamine, catechol-O-methyltransferase, and monoamine oxidase A. METHODS: We assessed 119 patients with unequivocal TLE with hippocampal sclerosis and 112 healthy volunteers. Individuals were genotyped for the polymorphisms of the gene encoding dopaminergic pathway transporter DAT haplotype, dopaminergic receptors, catechol-O-methyltransferase and monoamine oxidase A. We also evaluated epilepsy-related factors (e.g. seizure frequency, age of onset, duration and status epilepticus). RESULTS: There was no difference between the groups for the studied polymorphisms. The polymorphism DRD4_VNTR was associated with family history of epilepsy (P = 0.003), DRD2_rs1800497 was related to status epilepticus (P = 0.022), and intron 8 VNTR DAT was related to higher seizure frequency (P = 0.019) and family history of epilepsy (P = 0.011). CONCLUSIONS: Our findings demonstrated that polymorphisms of the dopaminergic pathway are associated with significant clinical features of this form of epilepsy, such as seizure frequency, family history of epilepsy and status epilepticus.

State-dependent microstructural white matter changes in drug-naïve patients with first-episode psychosis.

BACKGROUND: Diffusion tensor imaging (DTI) studies have consistently shown white matter (WM) microstructural abnormalities in schizophrenia. Whether or not such alterations could vary depending on clinical status (i.e. acute psychosis v. remission) remains to be investigated. METHODS: Twenty-five treatment-naïve first-episode psychosis (FEP) patients and 51 healthy-controls (HC) underwent MRI scanning at baseline. Twenty-one patients were re-scanned as soon as they achieved sustained remission of symptoms; 36 HC were also scanned twice. Rate-of-change maps of longitudinal DTI changes were calculated for in order to examine WM alterations associated with changes in clinical status. We conducted voxelwise analyses of fractional anisotropy (FA) and trace (TR) maps. RESULTS: At baseline, FEP presented reductions of FA in comparison with HC [p < 0.05, false-discovery rate (FDR)-corrected] affecting fronto-limbic WM and associative, projective and commissural fasciculi. After symptom remission, patients showed FA increase over time (p < 0.001, uncorrected) in some of the above WM tracts, namely the right anterior thalamic radiation, right uncinate fasciculus/inferior fronto-occipital fasciculus, and left inferior fronto-occipital fasciculus/inferior longitudinal fasciculus. We also found significant correlations between reductions in PANSS scores and FA increases over time (p < 0.05, FDR-corrected). CONCLUSIONS: WM changes affecting brain tracts critical to the integration of perceptual information, cognition and emotions are detectable soon after the onset of FEP and may partially reverse in direct relation to the remission of acute psychotic symptoms. Our findings reinforce the view that WM abnormalities in brain tracts are a key neurobiological feature of acute psychotic disorders, and recovery from such WM pathology can lead to amelioration of symptoms.

5-hydroxytryptamine1A receptor density in the hippocampus of patients with temporal lobe epilepsy is associated with disease duration.

BACKGROUND AND PURPOSE: To date, no study has evaluated the association between serotonin receptor density and clinical variables in patients with temporal lobe epilepsy caused by hippocampal sclerosis (TLE-HS) using hippocampal tissue. We evaluated 5-hydroxytryptamine1A receptor (5-HT1AR) density in hippocampal tissue from patients with TLE-HS. METHODS: We analyzed the hippocampal tissue of 34 patients with pharmacoresistant unilateral TLE-HS. 5-HT1AR density was measured using semiquantitative western blotting. RESULTS: There was an association between higher density of 5-HT1AR and longer duration of epilepsy (Spearman correlation: P = 0.040; generalized linear model: P = 0.026). CONCLUSIONS: This study demonstrated that hippocampal 5-HT1AR density is associated with epilepsy duration in patients with TLE-HS. The authors postulate that this may represent a potential regulatory enhancement of endogenous serotonergic neurotransmission in response to prolonged and enduring epileptiform activity in the hippocampal tissue of patients with pharmacoresistant TLE-HS.

A Selective Association between Central and Peripheral Lithium Levels in Remitters in Bipolar Depression: A 3T-(7) Li Magnetic Resonance Spectroscopy Study.

OBJECTIVE: The objective of this study was to evaluate brain lithium levels using (7) Li magnetic resonance spectroscopy after 6 weeks of lithium therapy in bipolar depression to test the hypothesis that brain and plasma lithium are correlated. It was also tested whether responders and remitters have different pharmacokinetics, blood and brain lithium levels (ratio) compared with those presenting suboptimal antidepressant improvement. METHOD: Twenty-three patients with bipolar disorder (I and II) during depressive episodes were included and followed up for 6 weeks at the University of Sao Paulo using flexible dose of lithium (450-900 mg/day). Sixteen patients were drug-naïve. At endpoint, patients underwent a (7) Li-MRS scan and brain lithium concentrations were calculated. RESULTS: A significant association between central and peripheral lithium levels was found only in remitters (r = 0.7, P = 0.004) but not in non-remitters (r = -0.12, P = 0.76). Also, brain lithium (but not plasma) was inversely correlated with age (r = -0.46, P = 0.025). Plasma lithium did not correlate with any clinical outcome, lithium dosage or adverse effects. CONCLUSION: These findings suggest that non-remitters may not transport lithium properly to the brain, which may underlie treatment resistance to lithium in BD. Future studies with (7) Li-MRS integrated with the evaluation of blood-brain barrier transport mechanisms and longitudinal clinical outcomes in BD and aging are warranted.

Cytochrome P450 genotypes are not associated with refractoriness to antipsychotic treatment.

Evidence validating the influence of the cytochrome P450 (CYP) 2D6 and 2C19 enzymes genetic polymorphisms in the response to antipsychotics is scarce. We examined the hypothesis that a higher prevalence of CYP2D6 and/or CYP2C19 ultra rapid metabolizers might be found among refractory schizophrenia patients. Three groups were studied: refractory and non-refractory schizophrenia patients, and healthy controls. Participants were genotyped for CYP2D6 and CYP2C19 polymorphisms and classified in metabolic phenotypes. No between-group differences in the distribution of the phenotypes were found. Therefore, our findings do not support the CYPs 2D6 and 2C19 genotyping in the prediction of therapeutic response in schizophrenia.

Increased iPLA2 activity and levels of phosphorylated GSK3B in platelets are associated with donepezil treatment in Alzheimer's disease patients.

Reduced phospholipase A2 (PLA2) activity and increased phosphorylation of glycogen synthase kinase 3B (GSK3B) participate in the production of beta-amyloid plaques and of neurofibrillary tangles, which are two neuropathological hallmarks of Alzheimer's disease (AD). Experimental evidences suggest a neuroprotective effect of the cholinesterase inhibitor donepezil in the treatment the disease. The aims of the present study were to evaluate in AD patients the effects of treatment with donepezil on PLA2 activity and GSK3B level. Thirty patients with AD were treated during 6 months with 10 mg daily of donepezil. Radio-enzymatic assays were used to measure PLA2 activity and Elisa assays for GSK3B level, both in platelets. Before treatment and after 3 and 6 months on donepezil, AD patients underwent a cognitive assessment and platelet samples were collected. Values were compared to a healthy control group of 42 sex- and age-matched elderly individuals. Before treatment, iPLA2 activity was lower in patients with AD as compared to controls (p < 0.001). At baseline, no differences were found in GSK3B level between both groups. After 3 and 6 months of treatment, we found a significant increase in iPLA2 activity (p = 0.015 and p < 0.001, respectively). iPLA2 increment was related to the cognitive improvement during treatment (p = 0.037). After 6 months, we found an increase in phosphorylated GSK3B (p = 0.02). The present findings suggest two possible mechanisms by which donepezil delays the progression of AD. The increment of iPLA2 activity may reduce the production of beta-amyloid plaques, whereas the phosphorylation of GSK3B inactivates the enzyme, reducing thus the phosphorylation of tau protein.

Translating neurotrophic and cellular plasticity: from pathophysiology to improved therapeutics for bipolar disorder.

OBJECTIVE: Bipolar disorder (BD) likely involves, at a molecular and cellular level, dysfunctions of critical neurotrophic, cellular plasticity and resilience pathways and neuroprotective processes. Therapeutic properties of mood stabilizers are presumed to result from a restoration of the function of these altered pathways and processes through a wide range of biochemical and molecular effects. We aimed to review the altered pathways and processes implicated in BD, such as neurotrophic factors, mitogen-activated protein kinases, Bcl-2, phosphoinositol signaling, intracellular calcium and glycogen synthase kinase-3. METHODS: We undertook a literature search of recent relevant journal articles, book chapter and reviews on neurodegeneration and neuroprotection in BD. Search words entered were 'brain-derived neurotrophic factor,''Bcl-2,''mitogen-activated protein kinases,''neuroprotection,''calcium,''bipolar disorder,''mania,' and 'depression.' RESULTS: The most consistent and replicated findings in the pathophysiology of BD may be classified as follows: i) calcium dysregulation, ii) mitochondrial/endoplasmic reticulum dysfunction, iii) glial and neuronal death/atrophy and iv) loss of neurotrophic/plasticity effects in brain areas critically involved in mood regulation. In addition, the evidence supports that treatment with mood stabilizers; in particular, lithium restores these pathophysiological changes. CONCLUSION: Bipolar disorder is associated with impairments in neurotrophic, cellular plasticity and resilience pathways as well as in neuroprotective processes. The evidence supports that treatment with mood stabilizers, in particular lithium, restores these pathophysiological changes. Studies that attempt to prevent (intervene before the onset of the molecular and cellular changes), treat (minimize severity of these deficits over time), and rectify (reverse molecular and cellular deficits) are promising therapeutic strategies for developing improved treatments for bipolar disorder.

Altered neurotrophin, neuropeptide, cytokines and nitric oxide levels in autism.

INTRODUCTION: Modifications in neurotrophins, neuropeptides, cytokines and nitric oxide (NO) levels in autism may represent different biological aspects of the disease. In the present study we investigate simultaneously all these variables as an attempt to clarify their interrelationships in autism. METHODS: Plasma levels of vasoactive intestinal peptide (VIP), neurotrophin-3 (NT-3), cytokines and nitric oxide (NO) were determined in children with DSM-IV autistic disorder (n = 24) and in age- and gender-matched healthy controls (n = 24). VIP, NT-3, IFN-γ and IL-1ß levels were measured by ELISA, TNF-α, IL-10, IL-6, IL-4, IL-2 were evaluated by fl ow cytometry, and NO by Griess reaction. RESULTS: Plasma levels of VIP, IFN-γ and NO were significantly higher and NT-3 plasma levels were significantly lower in children with autism, compared to the healthy subjects. In children with autism there was a positive correlation between plasma levels of NO and IFN-γ. DISCUSSION: Our results indicate the presence of altered levels of neurotrophin and neuropeptide in infantile autism and provide additional evidence that higher levels of IFN-γ may be associated with increased oxidative stress in autism.

Alterations of brain membranes in schizophrenia: impact of phospholipase A(2).

Physiological enzymatic cleavage of membrane phospholipids by phospholipase A2 (PLA2) results in normal levels of phosphomonoester and phosphodiester, by which a normal dopamine neurotransmission is maintained. Data from postmortem tissue and in vivo imaging studies suggest that increased activity of intracellular calcium-independent PLA2 (iPLA2) in the brain of schizophrenic patients might accelerate the breakdown of membrane phospholipids and alter the properties of neuronal membranes, which in turn contributes to a hypodopaminergy. Alterations in PLA2 activity are probably genetically determined and represent a possible pharmacological target for Schizophrenia.

Body mass index increase, serum leptin, adiponectin, neuropeptide Y and lipid levels during treatment with olanzapine and haloperidol.

INTRODUCTION: Body mass index (BMI) increase is an undesired effect associated with antipsychotics, and crucial for patients' global health and treatment compliance. We aimed to investigate the relation between BMI during olanzapine or haloperidol treatments and leptin, neuropeptide Y (NPY), adiponectin and lipid serum levels. METHODS: In this 9-month, randomized and naturalist study, 34 male patients, 18 on olanzapine and 16 on haloperidol group were enrolled, all were under monotherapy. Patient outcome was evaluated with positive and negative syndrome scale (PANSS) at every 3-month period. In each visit, BMI, leptin, NPY, lipid, olanzapine or haloperidol levels were also monitored. RESULTS AND DISCUSSION: Leptin levels positively correlated with BMI in olanzapine (r=0.64, p<0.001) and haloperidol (r=0.73, p<0.001) groups; only in olanzapine patients, the former also correlated with PANSS score (r=0.54, p<0.05). NPY levels negatively correlated with olanzapine levels (r=− 0.65, p<0.01). Adiponectin levels had not significantly varied. CONCLUSION: Antipsychotics probably interfere on leptin and NPY signalling ways and disturb these hormones in eating behaviour control.

Increased brain membrane fluidity in schizophrenia.

Recent findings showing significant correlations between phospholipase A2 (PLA2) activity and structural changes in schizophrenic brains contribute to the membrane hypothesis of schizophrenia, which was hampered because a clean functional link between elevated PLA2 activity and brain structure was missing (Neuroimage, 2010; 52: 1314-1327). We measured membrane fluidity parameters and found that brain membranes isolated from the prefrontal cortex of schizophrenic patients showed significantly increased flexibility of fatty acid chains. Our findings support a possible link between elevated PLA2 activity in cortical areas of schizophrenic patients and subsequent alterations of the biophysical parameters of neuronal membranes leading to structural changes in these areas.

Does the degree of smoking effect the severity of tardive dyskinesia? A longitudinal clinical trial.

BACKGROUND: Tardive dyskinesia (TD) is a movement disorder observed after chronic neuroleptic treatment. Smoking is presumed to increase the prevalence of TD. The question of a cause-effect-relationship between smoking and TD, however, remains to be answered. Purpose of this study was to examine the correlation between the degree of smoking and the severity of TD with respect to differences caused by medication. METHOD: We examined 60 patients suffering from schizophrenia and TD. We compared a clozapine-treated group with a group treated with typical neuroleptics. Movement disorders were assessed using the Abnormal-Involuntary-Movement-Scale and the technical device digital image processing, providing rater independent information on perioral movements. RESULTS: We found a strong correlation (.80

The neuroprotective effect of dental pulp cells in models of Alzheimer's and Parkinson's disease.

Aim of the present study was to investigate the neuroprotective effect of dental pulp cells (DPCs) in in vitro models of Alzheimer and Parkinson disease. Primary cultures of hippocampal and ventral mesencephalic neurons were treated for 24 h with amyloid beta (Abeta(1-42)) peptide 1-42 and 6-OHDA, respectively. DPCs isolated from adult rat incisors were previously cultured in tissue culture inserts and added to the neuron cultures 2 days prior to neurotoxin treatment. Cell viability was assessed by the MTT assay. The co-culture with DPCs significantly attenuated 6-OHDA and Abeta(1-42)-induced toxicity in primary cultures of mesencephalic and hippocampal neurons, and lead to an increase in neuronal viability in untreated cultures, suggesting a neurotrophic effect in both models. Furthermore, human dental pulp cells expressed a neuronal phenotype and produced the neurotrophic factors NGF, GDNF, BDNF, and BMP2 shown by microarray screening and antibody staining for the representative proteins. DPCs protected primary neurons in in vitro models of Alzheimer's and Parkinson's disease and can be viewed as possible candidates for studies on cell-based therapy.

Conditioning training and retrieval increase phospholipase A(2) activity in the cerebral cortex of rats.

In rats, phospholipase A(2) (PLA(2)) activity was found to be increased in the hippocampus immediately after training and retrieval of a contextual fear conditioning paradigm (step-down inhibitory avoidance [IA] task). In the present study we investigated whether PLA(2) is also activated in the cerebral cortex of rats in association with contextual fear learning and retrieval. We observed that IA training induces a rapid (immediately after training) and long-lasting (3 h after training) activation of PLA(2) in both frontal and parietal cortices. However, immediately after retrieval (measured 24 h after training), PLA(2) activity was increased just in the parietal cortex. These findings suggest that PLA(2) activity is differentially required in the frontal and parietal cortices for the mechanisms of contextual learning and retrieval. Because reduced brain PLA(2) activity has been reported in Alzheimer disease, our results suggest that stimulation of PLA(2) activity may offer new treatment strategies for this disease.

DNA polymorphisms as tools for spinal cord injury research.

STUDY DESIGN: Data mining of single nucleotide polymorphisms (SNPs) in gene pathways related to spinal cord injury (SCI). OBJECTIVES: To identify gene polymorphisms putatively implicated with neuronal damage evolution pathways, potentially useful to SCI study. SETTING: Departments of Psychiatry and Orthopedics, Faculdade de Medicina, Universidade de São Paulo, Brazil. METHODS: Genes involved with processes related to SCI, such as apoptosis, inflammatory response, axonogenesis, peripheral nervous system development and axon ensheathment, were determined by evaluating the 'Biological Process' annotation of Gene Ontology (GO). Each gene of these pathways was mapped using MapViewer, and gene coordinates were used to identify their polymorphisms in the SNP database. As a proof of concept, the frequency of subset of SNPs, located in four genes (ALOX12, APOE, BDNF and NINJ1) was evaluated in the DNA of a group of 28 SCI patients and 38 individuals with no SC lesions. RESULTS: We could identify a total of 95,276 SNPs in a set of 588 genes associated with the selected GO terms, including 3912 nucleotide alterations located in coding regions of genes. The five non-synonymous SNPs genotyped in our small group of patients, showed a significant frequency, reinforcing their potential use for the investigation of SCI evolution. CONCLUSION: Despite the importance of SNPs in many aspects of gene expression and protein activity, these gene alterations have not been explored in SCI research. Here we describe a set of potentially useful SNPs, some of which could underlie the genetic mechanisms involved in the post trauma spinal cord damage.

Centella asiatica water extract inhibits iPLA2 and cPLA2 activities in rat cerebellum.

Centella asiatica (L.) Urb an is distributed widely in South America and Asia and is known as a therapeutic agent in folk medicine, capable of improving memory and treating several neurological disorders. Asiaticoside is one of the compounds found in C. asiatica leaves that is suggested to be responsible for its pharmacological potential. Phospholipase A(2) (PLA(2)) is a group of enzymes that has abnormal activity in the central nervous system in some neuropsychiatric diseases. In this work, the asiaticoside present in C. asiatica water extract was quantified by HPLC analysis. We also evaluated the activity of subtypes of PLA(2) in cerebellar samples from rats after C. asiatica water extract treatment using a radioenzymatic assay. Asiaticoside was the major compound (84%) found in Centella water extract. We found a dose-dependent inhibitory effect of C. asiatica water extract on the activity of Ca(2+)-independent PLA(2) (iPLA(2)) and cytosolic PLA(2) (cPLA(2)). The inhibition of these enzymes in the brain suggests that C. asiatica may be useful to treat conditions associated with increased PLA(2) activity in the brain, such as epilepsy, stroke, multiple sclerosis and other neuropsychiatric disorders.

Requirement of hippocampal phospholipase A2 activity for long-term memory retrieval in rats.

In rats, the inhibition of phospholipase A(2) (PLA(2)) in hippocampus was reported to impair memory acquisition. In the present study we investigated in rats whether PLA(2) inhibition in hippocampus is also related to impairment of memory retrieval. Rats were bilaterally implanted with cannulae in hippocampal CA1 region. After recovery, animals were submitted to one-trial step-down inhibitory avoidance task and tested for long-term memory (LTM) 24 h later. Before test session, animals received infusions of vehicle or the PLA(2) inhibitor PACOCF(3). Inhibition of PLA(2) activity impaired LTM retrieval. Memory impairment was fully reversed once PLA(2) activity was recovered. Moreover, LTM retrieval per se increased PLA(2) activity. To our knowledge, we demonstrated for the first time that PLA(2) activity is required for memory retrieval. Because reduced PLA(2) activity has been found in Alzheimer's disease brains, the present results may be relevant to clarify at least part of the biology of this disorder.

The role of phospholipase A2 in neuronal homeostasis and memory formation: implications for the pathogenesis of Alzheimer's disease.

Phospholipase A(2) (PLA(2)) is a key enzyme in cerebral phospholipid metabolism. Preliminary post-mortem studies have shown that PLA(2) activity is decreased in frontal and parietal areas of the AD brain, which is in accordance with recent (31)P-Magnetic Resonance Spectroscopy evidence of reduced phospholipid turnover in the pre-frontal cortex of moderately demented AD patients. Such abnormality may also be observed in peripheral cells, and reduced PLA(2) activity in platelet membranes of AD patients, and correlates with the severity of dementia. In rat hippocampal slices, PLA(2) has been implicated in mechanisms of synaptic plasticity. In adult rats, the stereotaxic injection of PLA(2) inhibitors in the CA1 area of hippocampus impaired, in a dose-dependent manner, the formation of short- and long-term memory. Additionally, such inhibition resulted in a reduction of the fluidity of hippocampal membranes. In primary cultures of cortical and hippocampal neurons, the inhibition of PLA(2) precluded neurite outgrowth, and the sustained inhibition of the enzyme in mature cultures lead to loss of viability. Taken together, these findings reinforce the involvement of PLA(2) enzymes in neurodevelopment and neurodegeneration processes, and further suggest that reduced PLA(2) activity, probably reducing membrane phospholipids breakdown, may contribute to the memory impairment in AD.